Pacific ENSO Update

2nd Quarter, 2007 Vol. 13 No. 2

FSM Flag Federated States of Micronesia

Chuuk State: 1st Quarter rainfall amounts varied substantially across Chuuk State, with the highest totals in southern atolls (such as Ettal, Lukunoch, and Ta), and the lowest totals in northern atolls (such as Fananu, Onoun and Piis Panew). Rainfall totals near or below 5 inches in each of the months January, February and March at some northern atolls caused serious problems for residents where there was limited rainfall catchment storage capability. Also, the combination of high surf with high astronomical tides caused sea inundation of taro patches on several atolls. These conditions led to the Declaration of Disaster by the Chuuk State Government. Conditions were quite dry at Chuuk Lagoon and in the northern atolls for all of January through most of February. By early February it seemed that some of the atolls of Chuuk State would be in serious trouble because of a lack of rain. Later in February, however, a tropical disturbance moved through Chuuk State , accompanied by heavy rainfall that alleviated the dry conditions to all locations except the northern islands. In late March, the tropical depression that became Typhoon Kong-Rey moved through Chuuk State causing another episode of heavy rainfall at many locations.

Chuuk State Rainfall Summary 1st Quarter 2007

Station   Jan. Feb. Mar. 1st Qtr Predicted
Chuuk WSO Rainfall (inches) 3.92 9.01 13.26 26.19 18.91
% of Normal 37 % 147 % 148 % 102 % 75%

Piis Panew*

Rainfall (inches) 0.56 4.25 4.49 9.30 18.91
Xavier HS Rainfall (inches) 3.52 6.65 10.18 20.35 18.91

Lukunoch*

Rainfall (inches)

17.24

9.30 6.09 32.63 20.17
Ettal* Rainfall (inches) 11.00 10.58 14.75 36.33 20.17

Ta*

Rainfall (inches) 19.73 7.18 13.40 40.31 20.17

Fananu*

Rainfall (inches) 2.36 6.49 7.07 15.92 17.65
Onoun* Rainfall (inches) 7.61 4.86 4.77 17.24 17.65

Losap*

Rainfall (inches) 3.41 10.66 9.06 23.13 20.17

Nama*

Rainfall (inches) 6.14 13.61 6.90 26.65 20.17

Polowat

Rainfall (inches) 5.71 15.46 9.15 30.32 16.40
  % of Normal N/A N/A N/A 148% 80%
Predicted rainfall refers to forecast made in 4th Quarter PEAC Newsletter.
* Long term normal is not established for these sites
** Estimated

Climate Outlook: The anticipated onset of widespread El Niño-related dry conditions during the first quarter of 2007 did not occur in Chuuk, although some atolls in the northern portion of the state experienced a period of abnormally dry weather during January through mid-February. Problems with drought occurred at some of these northern atolls as rain catchment was substantially reduced. Two tropical disturbances (one in late February and one in late March ) alone provided enough rain to avert serious water problems in the northern atolls of Chuuk State. Rainfall amounts throughout most of Chuuk State should be near normal for the foreseeable future.

Predicted rainfall for Chuuk State from May 2007 through April 2008 is as follows:

Inclusive Period
% of Long-Term Average Rainfall
Chuuk Lagoon, Losap and Nama
Polowat
Northern Island
Mortlocks
May - Jul 2007
95%
95%
90%
95%
Aug - Oct 2007
100%
100%
95%
100%
Nov 2007 - Jan 2008
100%
100%
100%
100%
Feb - Apr 2008
110%
110%
100%
100%

source: UOG-WERI